include/asm-ppc64/mmu_context.h

   1 #ifndef __PPC64_MMU_CONTEXT_H
   2 #define __PPC64_MMU_CONTEXT_H
   3
   4 #include <linux/config.h>
   5 #include <linux/kernel.h>
   6 #include <linux/mm.h>
   7 #include <asm/mmu.h>
   8 #include <asm/cputable.h>
   9
  10 /*
  11  * Copyright (C) 2001 PPC 64 Team, IBM Corp
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License
  15  * as published by the Free Software Foundation; either version
  16  * 2 of the License, or (at your option) any later version.
  17  */
  18
  19 /*
  20  * Every architecture must define this function. It's the fastest
  21  * way of searching a 140-bit bitmap where the first 100 bits are
  22  * unlikely to be set. It's guaranteed that at least one of the 140
  23  * bits is cleared.
  24  */
  25 static inline int sched_find_first_bit(unsigned long *b)
  26 {
  27         if (unlikely(b[0]))
  28                 return __ffs(b[0]);
  29         if (unlikely(b[1]))
  30                 return __ffs(b[1]) + 64;
  31         return __ffs(b[2]) + 128;
  32 }
  33
  34 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
  35 {
  36 }
  37
  38 #define NO_CONTEXT      0
  39 #define MAX_CONTEXT     (0x100000-1)
  40
  41 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
  42 extern void destroy_context(struct mm_struct *mm);
  43
  44 extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
  45 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
  46
  47 /*
  48  * switch_mm is the entry point called from the architecture independent
  49  * code in kernel/sched.c
  50  */
  51 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  52                              struct task_struct *tsk)
  53 {
  54         if (!cpu_isset(smp_processor_id(), next->cpu_vm_mask))
  55                 cpu_set(smp_processor_id(), next->cpu_vm_mask);
  56
  57         /* No need to flush userspace segments if the mm doesnt change */
  58         if (prev == next)
  59                 return;
  60
  61 #ifdef CONFIG_ALTIVEC
  62         if (cpu_has_feature(CPU_FTR_ALTIVEC))
  63                 asm volatile ("dssall");
  64 #endif /* CONFIG_ALTIVEC */
  65
  66         if (cpu_has_feature(CPU_FTR_SLB))
  67                 switch_slb(tsk, next);
  68         else
  69                 switch_stab(tsk, next);
  70 }
  71
  72 #define deactivate_mm(tsk,mm)   do { } while (0)
  73
  74 /*
  75  * After we have set current->mm to a new value, this activates
  76  * the context for the new mm so we see the new mappings.
  77  */
  78 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  79 {
  80         unsigned long flags;
  81
  82         local_irq_save(flags);
  83         switch_mm(prev, next, current);
  84         local_irq_restore(flags);
  85 }
  86
  87 #endif /* __PPC64_MMU_CONTEXT_H */